Halogenated polysilanes are used, for example, to generate high-purity silicon in the semiconductor technology, for example, in the solar-cell industry. For this reason, very high purities are often needed for halogenated polysilanes. WO 2009/047238 A1 describes a process for preparing high-purity hexachlorodisilane where during the distillation of a mixture comprising hexachlorodisilane, water is present in amounts of not more than 10 ppbw (parts per billion per weight). WO '238 describes how the reaction of water with chlorosilanes may lead to the formation inter alia of disiloxanes, which have deleterious consequences for the purity of the desired hexachlorodisilane.
It could therefore be helpful to prepare halogenated polysilanes with increased purity which also satisfy, for example, the requirements for applications in photovoltaics.